Tiffany ate 2 slices of cake. Omar ate 2 slices. If Tiffany ate $\dfrac{2}{7}$ of the cake, what fraction of the cake was eaten?
Solution: If 2 slices represent $\dfrac{2}{7}$ of the cake, there must have been a total of 7 slices. $\text{fraction of cake eaten} = \dfrac{\text{number of slices eaten}}{\text{number of slices total}}$ They ate ${4}$ out of $7$ slices. They ate $\dfrac{4}{7}$ of the cake.